ABSTRACT Physical inactivity is a physical inactivity than risk factor for many important chronic diseases. Latino men report higher rates of non-Latinos, are less likely to meet PA guidelines and are disproportionately affected by PA-related health conditions, such as obesity and diabetes. Most Latino PA interventions have focused on women; the vast majority excluded men and none specifically targeted men. Moreover interventions that included men focused mostly on Mexican American only. Thus, there is an urgent need for effective PA interventions with diverse populations of Latino men. NIH has specifically called for research studies to focus on the development and testing of culturally appropriate health-promoting interventions to reduce health disparities among racially and ethnically diverse men. Our research team has 25 years of experience developing, implementing and evaluating individually tailored, theory-based, computer-driven PA interventions including `Seamos Saludables' (in RI) and `Pasos' (in CA), culturally and linguistically adapted, individually- tailored print (Seamos) and web-based (Pasos) interventions for a diverse population of sedentary Latina women that were successful in increasing PA in Latina women. We then conducted formative interviews with Latino men, which confirmed that an intervention would be well-received by them. However, substantial content modifications were needed, so we adapted the print intervention and tested it in a demonstration trial with 10 Mexican American men. After 12 weeks, participants reported a significant increase (p=.03) in mean minutes of PA from 1.50 min/week at baseline to 125.70 min/week at 12 weeks with 100% retention and expressed enthusiasm for the program. However, less than half of the men achieved the PA guidelines of 150 minutes/week. Thus, further enhancements appear to be needed. Follow-up interviews indicated that the intervention was well received, but the men felt that they needed greater accountability, more contact with staff and other participants, briefer and more frequent information, more updates on PA opportunities, and ideas for addressing environmental barriers. The men specifically mentioned interest in web and/or text-based interventions to meet these needs. Thus, we will conduct formative research with a diverse population of Latino men in RI to inform the adaptation of the Pasos web-based intervention that was developed for Latina women, enhance it with new cell phone/text-based intervention components, and ensure that it is culturally appropriate for Latino men of Caribbean, South and Central American origin. We will then conduct a pilot study to evaluate its feasibility, acceptability, and preliminary efficacy with a diverse population of Latino men in RI. In the pilot study, we will also explore potential moderators of treatment effects including demographics, acculturation, and environmental variables such as the neighborhood built, social and economic environments. The results of this pilot study will inform a future randomized controlled trial with Latino men to increase PA.